一直 vs 一向 (continuously vs habitually)

All day, or always?

• Your neighbour has been practising piano all morning; she has always been hard-working.
• she / her她tāalways一直yì zhíat / in在zài练琴liàn qín，she / her她tāhas always been一向yí xiàngvery很hěnto make an effort努力nǔ lì。 — "She's been practising the piano all along; she's always been hard-working."

always一直yì zhí = continuously (a stretch of time)

• always一直yì zhí = without a break over a stretch, past or future: always一直yì zhíat / in在zàito rain下雨xià yǔ, I我wǒwill会huìalways一直yì zhíwait for等děngyou你nǐ.
• It can also mean "straight": always一直yì zhíto walk走zǒu.

I我wǒwill会huìalways一直yì zhíwait for等děngyou你nǐ。

has always been一向yí xiàng = habitually, consistently (character)

• has always been一向yí xiàng describes long-standing habits or character from past to present: he他tāhas always been一向yí xiàngvery很hěnpunctual准时zhǔn shí.
• It does not look to the future: I我wǒwill会huìhas always been一向yí xiàngwait for等děngyou你nǐ ✗.

he他tāhas always been一向yí xiàngvery很hěnpunctual准时zhǔn shí。

Future and activities

Both possible

• he他tāalways一直yì zhí / has always been一向yí xiàngnot不bùliked喜欢xǐ huaneating吃chīspicy food辣là — both fine: a long-standing preference.
• has always been一向yí xiàng sounds more like a character trait; always一直yì zhí more like continuity.

he他tāhas always一向yí xiàngnot不bùliked喜欢xǐ huaneating吃chīspicy food辣là。

Recap

Read the full reference: HSK 6 grammar — Comparing similar adverbs.